Sewing machine with a device for lubricating the looper

Abstract

A looper lubricating device for a sewing machine includes an oil line having an inlet submerged within an oil supply and a capillary member within the oil line at a spaced location from the inlet and the oil supply. An outlet of the oil line is in fluid communication with an injection nozzle and the capillary member protrudes through the outlet of the oil line into a mixing chamber within the injection nozzle. A gas conduit communicating with the mixing chamber is operative to intermittently produce a pressure gradient between the inlet and the outlet of the oil line to pass oil to the mixing chamber.

What is claimed is: 
     
       1. An improved device for lubricating a looptaker of a sewing machine, comprising a storage vessel for containing a supply of oil, an injection nozzle having a mixing chamber for mixing a gas and the oil to form an oil mist and a discharge opening communicating with said chamber for passing the oil mist to the looptaker, an oil line having a bore extending therethrough from an inlet submerged within the supply of oil to an outlet in fluid communication with said mixing chamber, capillary means mounted within said bore coextensive over a zone of said oil line from a distance spaced from said inlet and the oil of the storage vessel and having an end portion protruding through said outlet into said mixing chamber, and means for intermittently injecting the gas under pressure into said mixing chamber such that a pressure gradient is created between said inlet and said outlet of said oil line and oil is passed into said oil line. 
     
     
       2. The improved device as set forth in claim 1, wherein said capillary means fills only a part of the flow cross-section of said oil line. 
     
     
       3. The improved device as set forth in claim 1, wherein said injection means comprises a conduit extending from a source of compressed gas and terminating in said mixing chamber adjacent said end portion, screw means connected to said injection nozzle and said conduit for securing said conduit for adjustment in said mixing chamber relative to said end portion. 
     
     
       4. The improved device as set forth in claim 3, wherein said capillary means comprises a wick. 
     
     
       5. The improved device as set forth in claim 4, wherein said oil line includes an end portion vertically extending in said storage vessel with said inlet submerged within the oil and said wick having an end disposed at a spaced distance above the oil. 
     
     
       6. The improved device as set forth in claim 1, wherein said injection nozzle includes a first bore for passing said oil to said mixing chamber and a second bore terminating in the mixing chamber at an oblique angle directed toward said discharge opening for discharging a stream of compressed gas into said mixing chamber and producing a partial vacuum to pass oil from said storage vessel to said mixing chamber. 
     
     
       7. The improved device as set forth in claim 6, wherein said injection means comprises a conduit extending from a source of compressed gas and terminating in said mixing chamber adjacent said end portion, screw means connected to said injection nozzle and said conduit for securing said conduit for adjustment in said mixing chamber relative to said end portion. 
     
     
       8. The improved device as set forth in claim 7, wherein said capillary means includes a wick, said end portion being partly disposed concentrically about a portion of said conduit in said mixing chamber.